Shelf



FIG. 1 shows a perspective view of my design for a shelf according tothe invention.

FIG. 2 shows a first side view, with the opposite side view beingidentical.

FIG. 3 shows a front view thereof.

FIG. 4 shows a top plan view thereof.

FIG. 5 shows a bottom plan view thereof; and,

FIG. 6 shows a back view thereof.

The ornamental design for a shelf, as shown and described.